Photographic apparatus



1935- L.' M. DlETERlCH PHOTOGRAPHIC APPARATUS 6 Sheets-Sheet 2 Filed Sept. 21, 1933 INVENTOR Ludwzl MDieZeI'L'C/z BY 65 L.

ATTORN EYS Dec. 31, 1935. M DETERICH 2,025,731

PHOTOGRAPHIG APPARATUS Filed Sept. 21, 1953 6 Sheets-Sheet 3 ATTORNEYS 1935. L. M. DIETERICH PHOTOGRAPHIC APPARATUS 6 Sheets-Sheet 4 Filed Sept. 21, 1953 INVENTOR I aulty. M .Db efercck dim/2M1; H9AWv ATTORNEYS /0 Jay 6.

L. M. DlETERiCH PHOTOGRAPHIC APPARATUS Filed Sept. 21, 1953 6 Sheets-Sheet 5 INVENTOR lungv y'flflieferiok @Zui MOM ATroRNEYs DEC. 31, 1935. L. M. DIETE 2,025,731

PHOTOGRAPHIC APPARATUS Filed Sept. 21, 1933 6 Sheets-Sheet 6 I I56 A 2 B l ATTORNEYS Patented Dec. 31, 1935 rnoroossrnrc APPARATUS Ludwig M. Dieterich, Lcs Angeles, Calif., assignor to The Dieterich Corporation, New York, N. Y.,

a corporation of New York Application September 21, 1933, Serial No. 690,349

a (c1. ss-iss) This invention relates to photographic apparatus and more particularly to apparatus for producing photographic pictures having relief or depth. r

This application is a continuation in part of my :gp lication Serial No. 217,127, filed September 2, 7 One of the objects of the invention is to provide a thoroughly practical apparatus for producing 10 photographic pictures having relief 7 or depth.

Another object is. to provide an apparatus by means of which there is produced upon a photographic film, plate or the like, an image in which the objects photographed stand out clearly in relief. Another object is to provide an apparatus of the above nature capable-of taking a picture in which the images of all the objects stand out with clearness irrespective of the distances of the objects from the apparatus when the picture is '20 taken.

Another object is to provide a photographic I apparatuscapable of producing a so-called negative" plate or film or the like having in itself relief or depth so that in a "positive" made there-.

5 from the images of the objects will stand out clearly in'relief.

Another object is to provide. a thoroughly practical apparatus for motion picture photography and which produces pictures having relief or depth. Another object is to provide a motion picture camera for taking a succession of pictures in v rapid sequence on a strip of film or the like and which dependably produces relief or depth in each picture. Another object is to provide an apparatus of the above nature which employs the usual motion picture film. Another object is to provide a motion picture camera of the above nature wherein the resulting negatives are developed-and thepositives are made therefrom in the usual 40-manner and inreadiness to be projected, without special apparatus.

7 Another object is to provide a motion picture camera which overcomesimany well-known difflculties ordinarily encountered in motion picture 45 photography and which produces pictm'es which,

when projected, are free from certain heretofore unavoidable and highly objectionabledefects; Another object is to provide apparatus of the above general nature which is thoroughly depend- 59 able. .Another objectis to provide apparatus of the above general nature which is compact in construction and simple to operate. Other objects will be in part obvious or in part pointed out hereinafter.

1 55 The invention accordingly in the fea-V tures of construction; combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims. 5 In the accompanying drawings in which are shown several illustrative embodiments of the various possible embodiments of this invention;

Figure 1 is a front elevation of a portion of a motion picture camera; 1 Figure 2 is a horizontal section taken substam tially as indicated by the section line 2-2 of Fig. 1, the camera box being broken away; N

Figure3isa viewfromtheupperedgeoi'l'is. 2, showing a portion only of the mechanism seen in Fig. 2; Figure 4 is a somewhat diagrammatic view on a small scale showing the motion"picture camera 7 in side elevation:

Figure 5 is a tie view for illustrating certain characteristics of a lens system;

Figure 6 is a side elevation, certain parts being broken away, of a motion picture camera construction embodying a modified and preferred form of lens construction and lens actuating m;

Figure 'l is an elevation as seen from the right in Figure 6, certain parts, however, being omitted in, order toshow certain features more clearly:

- Figure 8 is a horizontalsectional view on an enlargedscaleasseenalongthelineQ-lofll'lgure 7; g 7

Figure 9 is a central horizontal sectional view on an enlarged scale showing a preferred form oflens mounting and part of the preferred form 5 of lens moving mechanism;

.1'igure 10 is an enlarged end elevation as seen from the right in Figure 6, showing the relation of the light-controlling m of Figures 1 and 2 to the preferred form of lens construction and mounting;

Figure 11 is a detached fragmentary elevation the left of Figure 10 and shows more clearly certain of the operating mechanism A for the light-controlling mechanism, and y figure 12 is a ditic and graphic reprwentation of certain actions that take place in the lens system embodying the preferred forms of my'invention.

Similar reference characters refer to similar parts throughout the several views of the drawings. e 7

As conducive to a clearer understanding of thefeatures of my invention, it may be pointedout that a picture, as the art of photography is ordinarily practiced, the camera has to be "focused" upon the objects which it is desired shall stand out most clearly. and distinctly in the ultimate picture or photograph, and that in thus focussing the camera, the camera is adjusted upon or with respect to the particular plane in which the objects to be photographed mostnearly lie. All of the objects or portions thereof which may be considered to be in this plane upon which the lens system of the camera has been focussed will, in the re tant film or plate, or in the resultant pho I and distinct, while objects or other portions of objects which lie in front or in back of this plane or which .are nearer to or farther from the camera, will be relatively indistinct or blurred, or,

as is commonly said, out offocus- The greater the departure of the objects from coincidence with the plane uponwhich the camera has been focussed, the greater will be the blur. I term the above-mentioned plane upon which the lens system of the camera is focussed the plane of sharpness" because; as will be clear from the above, the objects which are in substantial coincidence with this plane are reproduced, in the image formed by the lens system, with greater sharpness and clarity than are objects positioned on either side of this plane. v 1

- It may be noted also that, inany film that has been exposed in an ordinary camera and developed, or in any positive or print made therefrom,

- the images of the objects photographed appear as of a relative size which depends upon various factors such as, for example, the characteristics of the lens system of the camera, the size of the objects, distances of the objects fromthecamera, and other factors. .Also, a change in the focus of a camera changes the sizes of the images of the objects. ;To make this more clear, let it be assumed by way-pf illustration that a camera is focussed upon a given plane and that an exposure is made. Images of the objects in that plane will be relatively sharply and clearly produced on the sensitized element of the camera,

' while images of other objects in the scene will berelatively obscure. If, now, such adjustments are made as will simplychange the focus of the camera in the usual manner, to focus the camera upon anew plane of sharpness either nearer to or. farther away from the camera, and, without moving the camera, a, second exposure of the already exposed sensitized element be made, the images of the objects produced by this second exposure will be of a different size from those produced by the first exposure; the objects which are in the new plane of sharpness, and whose sensitized element of a different size fromv the size of the images of the same objects ob-. tamed by the first exposure. .Thus, greater 1 images should appear relatively sharp and clear in the second exposure, appear in images on the blurring than ever would be produced byi'eason of the fact that changing of the focus brought about a change of size in the images of all of" the objects, successive exposures of the same sensitizedcamera element, with the camera sue-- cessively focussed on different planes of sharpness resulting in the superimposition of difierently dimensioned images of the objects. r

I have discovered thatby moving the lenses oi'alenssystem'in a certain manner relative to each other and/or relative to the sensitized cam- 'e'ra element, as I have more fully described in my application Serial No. 216,357, filed August 30, 1927, now Patent No. 1927525 am able to proph or print, be relatively clear" aoeavsi duce upon the sensitized camera element, by a second or subsequent exposure thereof, but with respect to a diflerent plane of sharpness than that of the first exposure, images of the same objects and which images will register in size with the corresponding images achieved by the first exposure; and by thus superimposing two such registering images I am able to produce a single-photographic negative plate or iilm in which the images have the characteristics as to 10 cleamess or sharpness that follow from the utilization ,of two 'diflerent planes of sharpness, it being clear 7 that thus a substantially equal sharpness and distinctness in the picture are achieved for such objects asare positioned in 15 these two planes and hence at two difierent distances from the camera. Thus, in the resulting negative or in a positive or print made therefrom, depth is achieved in that objects at two different distances from the camera are repro- 20 duced in the picture with substantially equal ment. And so, if I now superimpose upon the 3 sensitized camera element an infinite number of registering images taken with respect to an infinite number of diflerent planes of sharpness in the scene, all objects regardless of their distances from the camera are reproduced in images upon the sensitized camera element with substantially equal clearness and -sharpness. Any photographic positives or prints which I make from the sensitized camera element which, it should be noted, may be developed or otherwise treated g,

, in the usual way, will produce the visual depth .or relief of the original or negative.

f One of the dominant aims of the present invention is to provide an entirely practical photographic apparatus by means of which pictures having depth or relief may be achieved as has been briefly outlined in the foregoing, and in the drawings I have shown one of the various possible embodiments of such an apparatus. In the drawings there is shown a motion. picture camera since. my invention achieves particular advantages peculiar to motion pictures, but it is to be imderstood that the invention in its broader aspects is equally applicable to taking so-called still' pictures, snapshots, time exposures, b portrait work, and other classes of photography.

Referring now to the drawings, and first briefly to- Figure 4 thereof, there is shown on a small scale and somewhat diagrammatically .a. motion picture camera There is shown a camera casing 5- ill-mounted, for example, upon a suitable tripod ll. The film i2 isshown in dotted lines, passing from a reel it, through the camera and being wound upon a reel ll. Art the side of the camera boxthere is shown a crank l5 by means of which the camera is operated. Driven from this crank, among other mechanisms, is the mechanism for feeding the film and for operating th'e'shutter, this latter mechanism including a longitudinally extending shutter shaft, shown in dotted lines at 5 I 6, which will be referred to more particularly The mechanism for feeding the film is not shown in detail herein since it may take any of various'well-known forms and, in and of itself, its construction is not important as relating to this invention. It may be noted, however, that, in the camera here diagrammatically illustrated, the film l2 passes through two loops indicated at 11 and [8 in Figure 4, andithe exposures of the film are made as it passes between these two loops and is given an intermittent movement therebetween. The portion of the film approaching. the loop l8 and the portion thereofleaving the loop "has a continuous movement, the loops supplying the hecessary fullness to permit the intermittent movement of the portion between the loops. By means of a suitable shuttle mechanism, driven for example from the shaft I6, the portion of thefilm between the two loops 1'! and "is given the intermittent movement; the film is held stationary for a predetermined interval of time with a "frame" thereof in position.

- to be affected by the images formed by the lenses! :3 and during this interval the shutter (also driven by the shaftli) is open to expose the film; the

shutter then closes and the next frame..' of the film moves into operative position with respect to the lenses.

Referring now to FigureZ 7 there is shown the camera casing i'l, broen away, and the shutter shaft l8 extending alo e the casing and projecting forwardlythereof. ,por tion of the film I2 is shown in operativeiposition ftwith respect to the lens system, the film por--' tion passing through a shuttlemechanismdndicated at I! This shuttle mechanism-operates as described above to in termittently move the, .film and may take the form of .any of the various well-known mechanisms employed for this purpose. The shuttle mechanism is driven,'for example, by a cam or the like indicated at 2| upon the shutter shaft I i and connected to operate the shuttle mechanism through suitable'connections indicated at 2|. 1

At the front'end of the camera casing is a projecting-casing portion II which is substantially circular in shape and projects outwardly to the left of the body ofthe camera casing, as viewed from the front. The casing'portion ll has a front wall 22 through which the shutter shaft Ii projects and, mounted upon the shutter shaft just in advance of the wall 22 is the shutter 23. The shutter 22 takes the form of a circular plate mounted'upon' the shaft It to rotate therewith and having therein an arcuate slot 21 through which the light rays passing through the lens system are'admitted to the The wall 22 has therein an opening 2' for the 09 passage of the light rays to the film. As has been described in a brief way above, the rotating shutter 22 exposes the film during each stoppage thereof and shields the film during each intermittent movement thereof. It will be understood that the shutter 23 is shown herein in its simplest form and that it may befprovided with various adjustments and may take-various forms. The details of its construction are not important as relating to the features of this invention.

The lens system. as seen in Elgure 2, comprises four lenses 20, 21, 28 and 29, and the entire lens system is mounted upon a frontplate ll, as'will be described more particularly hereinaften. This :5 plate 2| rests against aplate Slandis rigidly fastened thereto as by means of screws 32. The plate II is circular in shape and fits within a forwardly projecting annular flange I06 of the easing portion NF; it is rotatable about the shutter shaft I6, which passes therethrough, and it has about its periphery a rearwardly extending flange 3|"- the edge of which bears against the outer surface of the wall 22. The portion l6 ofthe shutter-shaft is threaded and provided'wlth a nut 33. Between the nut 23 and the face of the 13 plate 2|! is a light spring washer 34.

The plate 3|, together with the plate 30 and the mechanisms carried thereby to be hereinafter described, is rotatable about the shaft It. The spring washer 34 holds the plate 3| with its flange 15 3h: firmly-against the wall 22 while at the same time permitting the plate to be rotated manually. This rotatable mounting permits the lens system to be swung manually about the axis of the shutter shaft Ii and thereby moved into and out of operative position before the film opening 25. In the drawings, the lens systemis-in operative position ready for taking pictures upon the film l2. The plate 3! is held in this position by a spring. pressed positioning plunger 25 which is mounted .upon the plate ll and takes into an opening 3'5 in the stationary wall 22. The plunger 25 may y be withdrawn against the action of thespring and thereupon the plates 30 and 2| carrying the of. th drawings,

lenses may be rotated to move'the lenses into any desired position about the axis of the shaft It. For example, the plates may be swimg until the lenses are positioned in front of an opening 31 which is provided in the wall 22 diametrically op-' the opening 25 therein. When the lenses :.;are swung into sucha position it is possible for the operator to look through a suitable opening indicated at I! and view through the lenses themselves the scene which is to be photographed. A number of openings similar to the opening 26 are provided in the wall 22 for cooperating with the plimger 35 so as to locate the lenses in whatever positions may be desired about the axis of the shaft I6.

Still referring to Figure 2, the lenses --system are seen to be contained within a cylinder or tube II which projects outwardly from the face of the plate 30. The tube is fastened to the plate by means of a suitable flange 49,- and the rear end thereof projects into registering openings in the plates 29 and 3| which, in the operative position a of the parts shown, are alined with the opening 25 in back of which is positioned the film. The front 7 lens 26 is held in a bushing 4! which is threaded into the front end of the tube. The two rear lenses 28 and 2! are held ina bushing 42 which is threaded-into the rear end of the tube. These 1 three lenses are thus rigidly mounted and fixed in position relative to each other and relative to the operative portion of the film. The lens 21 is ca movable of the lens system relative to the other lenses and relative to theifilm. Preferably thelens 2l isheld in a bracket 43 from-'whichextends a radial arm passing thro a lon i- "tudinal slot 4E5 in the side of the tube 39 facing toward the shutter shaft l6. Thus, by means of the arm 44 the lens 21 may be moved back and forth axially of the lens system. 4

The movable lens 21, as is hereinafter amplifled or explained .in greater detail, is of special construction and has the characteristic, in its combination with or relation to the other lenses of the lens system, that movement thereof axially changes the focus but does not alter the size of the of the lens -13 element or film.

I have discovered that, with a lens system such as that illustrated in the drawings, and having the above-mentioned special construction and characteristics, all more in detail set forth hereinafter, by moving the lens corresponding to the lens 21 axially in the manner above described, I am enabled to change the focus of the lens system, and to bring into sharpness in' the image formed by the lens system objects positioned in the scene at different distances from the lens system, and without changing the sizes of the images of the objects. For different axial positions of the lens 21 different planes at different distances from the camera are brought into sharpness in the image afiecting the film l2 and, throughout, thesizes of the images of the various objects in the scene, affecting the film i2, remain substantially I constant. Thus, by moving the lens 21 in an anal direction while the shutter 23 is open and a frame" of the film I 2 is thus exposed I'accomvplish, in effect, the superimposition of a number tions of objects lying between any two desired planes in the scene. Preferably, for ordinary photography, I give. the lens such a movement as will bring into effect, in the image, planes of sharpness extending from a plane near the camera to a plane at an nite distance away. Regardless of the limits of the lens movement, all the planes (infinite in number), between the two :limits of the plane nearest to the camera and the plane farthest away, are brought into sharpness in the image which effects the film. Thus, all of the objects and parts of objects whichare photographed appear in the resulting image upon the film with substantially equal sharpness, and the depth or relief is achieved.

The lens 26 is the positive front lens and a planoconvex lens, the lens 21 is the negative lens and is a double concave lens, the lens 28 is a concavoconvex lens, and the lens 29 is a double convex lens; lenses 28 and 29 make up the corrective lens. This type of lens system is found to give excellent results, but it is to be understood that other types I of lens systems may be employed to advantage.

Referring again to Figure 2 of the drawings, the arm is rigidly fastened at its outer end, for example by means of screws 46, to a sleeve" which is slidably mounted upon-a post 48. The post I8 is rigidly mounted upon the plate 30' and projects forwardly therefrom with its axis .exactly parallel to the axis of the lens system. secured to the sleeve 41 is a bracket 49 which is fastened theretoby means of screws 50, for example. Projecting from the bracket 49 toward the shutter shaft I6 is a split ing it in which is ,an adjust able screw 52, clamped by aclamp ng Screw- 53,

. The shutter shaft l8 -hasja forward end portion i8 upon which is secured a cam 54 having a forwardly facing cam surface 55 which acts against the end of the screw. 52. Aboutthe end of the post 48 is a-coiled spring 55 which bearsagainst aocavai images of the objects formed by the lens system at the image plane or upon the sensitized camera the end of the sleeve 41 and is provided with an adjusting nut Bi'threaded upon the end of the post. The spring 56 holds the screw 52. against the cam surface 55 and this cam surface thus determines the axial position of the lens 21. The cam 55, rotating with the shutter shaft l6, gives the lens 21 an axial movement in one direction and back again during each rotation of the shutter shaft. The cam is so designed that it will give the lens a movement such as will bring into 10 sharpness in the image all the planes in the entire scene or all of such planes as pass through the objects which it is desired to reproduce sharply in the picture. The range of movement of the lens is adjustable by means of the adjusting screw 15 52 which is firmly locked in position by means of the locking screw 53, after adjustment.

Referring to Figure 1 of the drawings, projecting downwardly from the sleeve 41 is an arm 58 having a finished surface 59 which bears against 20 acting between the end of the arm 58 and a pin 55 projecting from the plate 30, holds the surface 25 60 against the surface 59. The coacting arm 58 and post 6| hold the sleeve 41 from turning about the post 58 and guide the sleeve 41 in its sliding movements. The surface 50 of the post 6| is parallel to the axis of the lens system and thus, 30 as the lens 21 is given its axial movement, it is dependably held in accurate coaxial relation with the other lenses. A slight twisting or other movement of the lens 21 out of its proper axial position would interfere with the properaction of the lens 5 system in producing a clear image.

The cam surface 55 thus gives the lens 21 an. axial movement in one direction and bacl: again to its original position with each rotation of the shutter shaft l6. As has been described above, 40 during each rotation of the shutter shaft, the shutter is open to expose the film for a predetermined interval of time and is closed to shield the film duringthe remainder of its rotation and 1 while the film is being moved by the shuttle mechanism to bring the next frame thereof into position to be aifected by the-images formed by the lens system. Preferably, the relation between the cam surface 55 and the shutter 23 upon the shutter shaft I6 is such that the lens 21 is given its 50 movement in one direction while the film is exposed and is returned in the opposite direction while the shutter is closed. Thus, in each of the successive pictures impressed upon the strip of film l2, there is dependably produced depth or 55 relief. As each picture is taken, the lens 21 is moved so as to successively bring into sharpness in the image afiecting the film, objects lying in planes atvarying distances away. Moreover, the. sizes of the images of all the objects remain substantially constant and therefore, all of the ob jects. regardless of their varying distances from 66 is a hardened plate 61 forming part of a lever 58. The lever 681s pivoted upon a stud. projecting outwardly from the plate 30, and is held against the cam surface 66 by means of a spring I0 bearing against the end portion 68! of the lever. in the end portion 68 of the lever 68 is a hardened 7 plate 1| which bears against a pin 12 projecting from a slide 18. The slide 18, as shown in Figure 3, is supported in a block 14 secured to the face of the plate 88 above the lenses. Secured to the slide 18 by means of screws 18 is a flat blade-like member 18 which projects downwardly in front of the sleeve 88 in which the lenses are mounted. Beneath the lenses is a slide 11 similar to the slide 18 and mounted in a block 18 similar to the block 14. The slide 11 carries a blade 18 similar to the blade 18 and secured to the slide 11 by means of screws 88. The blades 18 and 18 are substantially alined and their ends project toward each other adjacent to the front end of the sleeve 88.

Secured to the slide 18 by means of screws 8| is a cross-arm". Bearing against the projecting right-hand portion of the arm 82, as viewed in Figure 1 of the drawings, is a strut 88, the other end of which bears against a lever 84. The lever 84 is pivoted upon a stud 85 projecting from the plate 88 and has a hardened insert 88 which bears against a pin 81 projecting from the slide 11. A spring 88 bears downwardly (as viewed in Figure 1) against a pin 88 on the slide 11 and thus tends to swing the lever 84 in a counter-clockwise direction so that the strut 88 is held in position between the lever 84 and the arm 82.

As the cam surface 88 rotates, the lever 88 rocks about its pivot 88, the right-hand end thereof (as viewed in Figure 1) moving up and down. This movement of the lever 88 imparts, through the connections just described, an up and down movement to the two slides 18 and 11, the slides moving toward each other and then away from each other to alternately decrease and enlarge the distance between the adjacent edges of the blades 18 and 18. In order to steady this movement and counteract any binding effect upon the slide 18, a spring 88 is provided acting upon the end portion of the arm 82 againstthe action of the spring 18.

In the right-hand end portion of the arm 82 is a hardened piece 8| which engages with a rounded projection 82 on a bell crank lever 83. The lever 83 .is pivoted upon a pin 84 projecting from the plate 38, and a spring 85 holds the projection 82 against the surface 8|. Upon the other arm of the bell crank 88 is a blade-like plate 88 loosely fastened thereon by means of a single screw 81. Projecting rearwardly from the blade 88 is a bracket 88 from'which extends. an

varm 88. The arm 88 slidably enters an opening through a bracket I88 which is secured to the plate 38 by means of screws I8I.

In the left-hand portion of the arm 82 (as viewed in Figure 1) is a hardened piece I82 similar to the piece 8|. This hardened piece I82 is engaged by a rounded projection I88 on a bell crank lever I84. The lever I84 is pivoted upon a pin I85 projecting from the plate 88 and the projection I88 is held against the hardened part I82 by means of a spring I88. On the other arm of the bell crank I84 is loosely fastened, by

means of a single screw I81, a blade-like plate I88 similar tothe plate 88. r

The plate I88 overlaps the two plates 18 and 18 and its inner edge faces the inner edge of the plate or blade 88, the two blades I88 and 88 being positioned in the same plane; Adjacent their upper edges the two plates 88 and I88 are connected by a spring I88 stretched between a pair of pins III and III; adjacent their lower edges these two plates are connected by a spring II2 stretched between a pair of pins H8 and H4.

' The plates 88 and I88 are permittedto swivel opening I I5.

about the respective screws 81 and I81, and the springs I88 and H2 are adapted to keep their adjacent edges always substantially parallel.

As seen in Figure 1, the four plates 18, 18, 88 and I88 form between their inner'e'dges an open- 5 ing II5 which is substantially in line with the axis of the lens system and positioned directly in front of the lens" system. The light rays which pass through the lens system to affect the film are admitted thereto through. this opening III. 10 Preferably, the opening between the plates or blades is rectangular in shape and therefore of substantially the same shape as the film surface which is exposed. As has been described above, as the shutter shaft I6 rotates, the up and down movement imparted to the lever 88 by the'cam surface 88 causes the plates 18 and 18 to move toward and away from each other. As the slide 18 reciprocates, the arm 82, moving therewith, swings the two bell cranks 88 and I84 about their 20 pivots, and the two plates 88 and 188 are moved toward and away from each other. All of the plates move inwardly together toward the axis of the lens system and all move outwardly together and thereby the size of the opening I I5 is alternately decreased and increased as the shutter shaft I8 rotates. The parts are so proportioned that each of the four plates moves substantially the same distance for a given swing of the lever 88 and thus the rectangular shape of the 39 opening 5 is continually preserved.

The size of the opening 8 determines the amount of light admitted to the film through the lens system. The cam surface 88 is so related to the cam surface 58 that, as the lens 21 is moved to bring into sharpness, in the image, planes at an increasing distance away, the plates 18, 18, 88 and I88 are moved to increase the size of the Thus, as objects at varying distances from the camera are broughtintosharp- 40 ness in the image affecting the film, the amount of light admitted to the film is changed, the amount of light being increased for objects relatively far away and being decreased for objects. relatively near. In this manner, the proper re- 4 production of the image upon the film throughout the range of movement of the moving lens 21 is dependably assured.

It will be seen that the mechanism above described is simple and compact and capable of highly efficient and accurate operation. The position of the movable lens 21 in proper coaxial relation to the lens system is dependably maintained so that proper functioning of the lens system throughout is assured. Also, the mechanism provides for convenient adjustment of the range of movement of the moving lens to meet varying conditions of practical operation. The mechanism shown and described is capable of operating eificiently and denendably at any speed corresponding to which it may be desired to operate the motion picture camera. The films after exposure have impressed thereon images which have natural and visual depth. The negative films may be developed or otherwise treated in the usual manner and, when positives or prints are made from the films in the-usual manner, these positives have the depth or relief of the original or negative. When my invention is utilized in a motion picture camera, as described herein, the positives made from the original or negative strip of film are projected in thensua'l motion picture projection machine and the-pro- It has been mentioned above that my invention achieves particular advantages in the field of motion picture photography. In present day motion picture photography, when an object is in motion in the field of the camera, and particularly when the motion of the object is transversely of or across the field of the camera while-the camera is focussed in the usual manner upon the of the camera, may be considered. Thus, at 88 I have shown a single point from which light rays pass through the-lens system to affect the sensitized camera element positioned in the plane I55. A light ray, emanating from the point I55, 5 is indicated at I56; it-passes through the first principal focal point I50 and, upon reaching the first principal plane I52 it has its direction changed as indicated by the line I, striking the image plane IE4 at I51. Another light ray 1 moving object, the motion that takes place dur- 553 passes directly through the lenses, in a path ing exposure of a single frame" of the film pro duces upon the frame" a series of relatively dis- .placed superimposed and non-registering images of the moving object, all, of the images standing out with almost the same degree of sharpness 'because of the fact that the image is moving in field'of the camera and relatively close to the progressivelyaway fromthe moving object.- Accordingly, the displaced positions of the moving object, if reproduced at all upon the film, are impressed upon the latter with an increasing lack of clarity and sharpness. I thus eliminate the blurring eiiect. of so-called cross motion, an efiect heretofore considered unavoidable and one of a representative camera lenssystem. Re-

renting to Figure 5 of the'drawing's, I have shown the four lenses 26, 2'8, 28 and 29, In this p'ar- .ticular lens system, the first lens group consist- .ing of the lenses 26 and'l'i is constituted of the lenses which produce the image and which may @becalled the imaging lenses, and the second lens group consisting of the lenses 28 and, 29 is constituted of lenses which. correct certain errors and which may be called corrective lenses. The lens system may have any suitable number of lens groups. In accordance with the understanding of those skilled in the art of photography,

; it is assumed that such'an illustrative lens system-'haswhat is called a "first principal focal poin which is indicated in'the drawings at I50,

and a ,second principal focal point"; which is indicated at til {itis also assumed that the lens system has what is called a first principal plane" and whatis called a fsecond principal 'plane These two planes are indicated at I52 and I53 respectively. The i mage plane",'or the plane at which the sensitized camera element, such as the plate or fiim,'is positioned'known also as the conjugate focal plane",ls indicated at Ill.

In'order to make these characteristics of these lens systems a little'niorecleanr-their relation with respect toe point-or object; the range parallel to the center line of the lens system, to f the second principal plane I53 from which, with its direction changed as indicatedby the line I58 it passes through the second principal focal 15 point iti and strikes the image plane IE6 at the same point i 51 at which the'light ray II strikes the image planie and at which point an e of the object '(the'ipolnt I55) is formed.

The distances. between the first principal focal 2 point Isa-and the first principal plane I52 is called-"the first equivalent focal length; the 3 between thesecond'principalfocai point Iii and-the second principal plane I58 'is called the second equivalent focal length. The 25 distance 0 between the second principal plane and the image plane is called the second coniugate focal length. The dIstanceEbetween the rearmost point of the rearmost lens 29 of the'system andthe image plane IE5 is called the "back 30 focal length. Still referring to the art of photography as it is practiced in present day methods, when a. camera is focussedvupon an object, or more cor= rectly. upon a plane, the lenses of the lens system, 35

incertain fixed positions relative to one another, are in a certain position relative to the sensitized camera element, and the focal lengths mentioned above have certain values. If, as has been explained hereinbefore, the position of the lens sys- 4 tem is now adjusted inmown manner, that is by appropriate adjustment in an axial direction of the lens system as a unit relative to the image plane I56, so as simply to change the focus of the camera,'the images ofjobiectsJn the scene 5 produced at theimage plane I 56 change inslge. Such adiustments to change the focus of a lens system-in'known manner, effect certain changes in the focal values discussed above, which it is not necessary to discuss-in detail herein. 7. v 1

As for the theory of my invention, briefly considered, as I now understand the theory of what takes place when I make such adjustments that diflerent' planes in the scene are brought into sharpness in the image, all without changingthe 55 sizes ofthe images of the objects in the scene, I .am effecting among other things a change in the second'ei iuivalent focal length B without chang-. ing the position of the second principal plane I53 relative to the image plane I54. V g In this connection, it might, 'however,be of aid to pointcut that, when the entire lens system in a camera is shifted, according to known methods, the resultant change in focus is accompanied ;.by change in size of theimage. sum *shiiting-ofthe lens system see whole results in shifting the principal planes of the lens system and also the principalfoci, resulting irrout-of focus images thatare made up of circles of-confusion which are eccentric to the in-focus point 'images'that make up'an in-focus image. This eccentricity means not only change in' size but non-registry of out-of-focus and in-focus images if-impressed upon the same film or plate. Now,

ithas been proposed, butfor diil'erent ourposeaje' to make movable and to shift one component lens of a lens" system in a camera, and here again, change in focus results and is again accompanied by change in size of image, the out-of-focus images being again made up of circles of confusion which are eccentric to the in-focus point images that make up an in-focus image of an object or scene; here, also, a shifting of principal planes and of the principal foci takes place and the results are substantially similar to those just mentioned in the'case of shifting of the entire lens system.

In contrast, however, to such known phenomena or such known apparatus, the lens group of my invention embodies lens components, one of which (the negative lens) is movable relative to the other and is moved during exposure, which, by the use of known methods of correctionand computation, are corrected to avoid shifting of principal planes though the focus is changed, thus achieving change in focus during the exposure without, however, changing the size of in-focus and out-offocus images of the scene or object to which the film plate or sensitized photographic element is thus exposed through the lens group; in further contrast to such known phenomena or apparatus as I have mentioned immediately above, the avoidance of a shift in the principal planes while changing the focus results in out-of-focus images of points in the scene or object that are made up of circles of confusion which are concentric (not eccentric) with the in-focus images ofthe same respective points. For eachone of the infinite number of planes of sharpness throughout thedepth of the scene and hence for each corresponding focal length, there is impressed upon the sensitized element an in-focus image with respect to which all other and. hence out-of-focus images of the same scene are made up of circles of confusion which are concentric with the corresponding and respective points of the in-focus image. 'This concentricity means constancy of size of the multitude of in-focus and out-of-focus images as well as registry thereof on the sensitized camera element. The correction of the lenes of the lens group to achieve ,in coaction such eoncentricity may be effected by any known graphic or computing methods.

I have above pointed out, with reference to Figure 5, that shifting of the movable lens 21 along the optical axis changes the focal length B without, however, causing a change in the position of the second principal plane I53 relative to the stationary lenses 26, 28 and 29 and relative to the film plane l54 and that, due to these considerations, the sizes of successive images are identically the same althougheach image corresponds-to a different plane of sharpness. The

- principal plane, therefore, remains fixed and the principal focal point shifts; thelenses, in construction, are therefore correspondingly correct ed, using any known method of lens computation. When so corrected, therefore, the light rays, in passing through the lens system during movement of the movable lens, are bent or controlled and strike the image. plane in pencils that give circles of confusion for the out-of-focus images that are concentric with the in-focus point images that make up an in-focus image of the scene or object. Due tojJthis concentricity constancy of size of in-focus and out-of-focus images results.

Now making reference to Figure 12, all of Figure .5 is reproduced (the lenses, however, .being .shown diagrammatically), thus to show the point image I51 of the object point I55, exactly as it is achieved in Figure l by a consideration of the four cardinal factors of the lens system; however, let it now be considered that the lens 21 is shifted to the right. The focal length B in accordance with the optical prescription above stated, permitted to change but without changing the position of the principal plane I53 relative to the lenses 25, 28 and 29 and relative to the film plane I 54; The secondprincipal focal 10 point I 5| is thus moved to the position I5l', being moved toward the optical center of the lens system and a commensurate shifting toward the optical center of the first principal focal point I50 takes place, namely to the position I58. No shifting in the principal planes takes place. Light ray I58, after this shift in the lens 21, strikes confusion XX whose center is spaced from the optical axis by exactly the same distance as the spacing of the point image I51 from the opticalaxis. The point image I51 and the circle of 'con- 30 fusion XX are concentric. No change in size of the new image results because of this concentric relation.

Thus, the full-line representation in Figure 12 I and hence also that of Figure 5 may be considered to represent graphically what happens when the lens system having the special characteristics above pointed out has its movable component 21 positioned so that the camerais now focused on the point object I55, or, stated differently, when the plane of sharpness is spaced from the film plane I54 by the same distanc as the spacing therefrom of the point object I55 while the broken lines of Figure 12 show diagrammatically what happens to light rays emanating from the fixed 4:, point object I55 when the movable component 21 of the lens system is shifted to change the focus of the system so as to bring into effect a plane of sharpness whose distance from the film plane I54 is different from the distance therefrom of the point object I55. So-called circles of confusion are considerations characteristic of all photographic lenses but in so far as I am aware.

no lens system, has heretofore been produced in which \the above-mentioned conoentricity, achieved by changing focal length without shift of the principal plane, has been brought about.

No matter what the change in focus'or shifting of the plane of sharpness away from the plane of sharpness through the object point i55, the circle of confusion always stays concentric to the point image I51. correspondingly, this permanent concentricity establishes the fact that the size ofthe image of an objectin the photographic field of my preferred form of lens system remains constant for all values of focus.

I have above pointed out that, as is well known, change in the focus of a lens system of known type or types when employed in a camera results in change of size of image, where change of focus is achieved by such known methods as shifting the entire lens system relative to the sensitive surface, or shifting one of the lenses of a lens system, or otherwise. Now, such change of size of image arises out of the fact that, with such known methods or systems of changing focus, circles of confusion are produced on the sensitive surface that are eccentric with respect to the in-focus ima' e.of the point or points corresponding to whic when the focus is changed, the outer focus circles of confusion are produced. This eccentricity, inevitably, therefore,

Q I causes change in size of the out-of-focus image.

These vital deficiencies of known methods or apparatus I. overcome in my invention in making certain that the out-of-focus circles of confusion are always concentric with the in-focus image of the corresponding point or points, as is perhaps more clearly shown graphically in Figure 12.

- The lens system'of Figures andgl2 employed in carrying out my invention, is, therefore, computed and corrected with known methods, by the lens-computer, on the .basis of the maintenance of constancy of size of image (and hence the maintenance of the above-mentioned concentricity) for all positions of the movable lens 27 (within its. limited range of movement) while maintaining in fixed position the principal plangj Further detailed data, particularly with respect to a preferred illustrative embodimentv of the lens system of my camera, is set forth hereinafter but before further discussing the lens system, the construction and'action of which is now clear in view of the foregoing, I wish to refer to and describe a modified form of certain of the mechanism above described in connection with Figures 1', 2 and 3 and shown in detail in Figures 6, '7, 8,

' and, 11.

Accordingly, referring first to Figures 6 and 7,

camera somewhat different from the type of motion picture camera described above in connection with Figures 1 and 2. Therelis again shown which is mounted on a hollow base 200, the latter being adapted to be carried upon a tripod, such as the tripod ll of Figure ,4, and having at its forward (right-hand end as viewed in Figure 6) end an upright hollow frame portion the camera casing l0 being slidably carried by the parts 20020I, as in the ways 202-203.

'Ihecamera casing I0 is provided with the usual crank 15 (Figure 6) by means of which the camera is operated and the variousmechanisms, such as the film-feeding mechanism, the shutteroperating mechanism, and other parts,,are driven. Insofar as the "structural details of these mechanisms are concerned, these need not be further described inasmuch as they are well known in the art, the particular camera construction being a well-known commercial form of apparatus; an

illustrative form of shutter mechanism and film- I moving mechanismahas been above described in connection with Figures 2 and 3 and that might be considered, for illustrative purposes, as being 204 mounted one. shaft 205; to this mechanism I attach, preferablygpn the flywheel shaft 205, a cam 208, the purpose and function of which are described in detailh'ereinafter.

- Upon the front or vertical portion '20 of the frame is rotatably mounted a disk-like plate 201 (correspondingto the plate of Figure 2) suitably provided with means for holding a suitable number of lens or lens systems illustratively and diagrammatically indicated in Figure 'l at z, y,

and z and an illustrative embodiment of the lens system of my invention (as later described), the plate 201 being rotatably carried by a suitable pivot 208 whereby any one of the various lens a systems carried by the plate may be positioned for coaction with the film and related mechanism. the film gate (not shown) and shutter (not shown) being eifective at the right-hand side of the camera as the latter is viewed in Figure '7. 10 Upon this plate 201 is mounted my lens system and related parts, and certain preferred features of the mechanical parts of my lens system are better shown in Figure 9.

Referring now to Figure 9, I provide a tube- 15,

like housing or-sleeve 209 provided with a pe ripheral flange 2l0 adjacent its left-hand end, adapted to rest against the plate 20'! (Figures 6 and 7), the left-hand portion of the sleeve 209 I being received in one of the various lens-receiving 20.

apertures in the rotatable plate 20?; reference to Figure .7 shows the left-hand end of the sleeve 209 received in an aperture 20'! in the plate 20?, v

the flange 2i 0 resting against the latter and being secured thereto as by screws 2! I.

The inside face 299 (Figure 9) of the sleeve 209 is bored out to provide a nice bearing surface for slidably receiving an auxiliary sleeve 212, both sleeves being of substantial axial extent and thus permitting accurate relative move- 30, ment therebetween-while maintaining their axes geometrically coaxial during such movement.

Auxiliary sleeve 2l2 has, intermediate its ends; an annulus M3, to which is suitably secured or in which is suitably mounted a lens 2'21 (corre- 35. sponding to the. lens 21 of Figure 5), this lens 221, being related to and coacting with lenses 226, 228 and 229 (correspondingrespectively to the lenses 26, 28 and 29 earlier above described),

Consideringfor the'present the mounting of 40 these coacting lenses, lens 226 is mounted in the inner end of a bushing or lens mount 2 whose right-hand end, as viewed in Figure '9, is threaded into the right-hand end of the fixed housing or sleeve 209, lens- 22S being thus made stationary. Lenses 228 and 229 are mounted in the inner end of a tube-like bushing or lens mount 2B5 whose left-hand end, as viewed in Figure 9, is threaded into the left-hand end of the sleeve 209, these two lenses being thus also held stationary. Any

suitable means may be employed to hold these various lenses in their respective lens supports or mounts, as will be understood by those skilled in the art, Figure 9 showing in detail possible mechanical expedients for securing each of the four Q5; lenses in their respective holders or mounts. The 0 individual lenses, being preferably and conveniently mounted, are mounted so that their respective optical axes are coincident with the mechanical axis of the bushings or tube-like mounts'in which they are res ctively supported while the mounts themselves are in turn all related to the main supporting sleeve- 209 so that their axes are coincident with the axis voi! the sleeve 20!, and thus coincidence of the optical Q5} axes of the diflerent'lenses employed is easily achieved and maintained.

When, therefore, the plate20l (Figures 6 and 7) is rotated to the position shown in Figure "I and suitably fixed in that position, the lens .gys-

tern above described in connection with Figure ,9 ispositioned in alinement with the fllm gate and the locus of'operation of the shutter, the parts assuming a relation similar to the rela u tion of the analogous parts as shown in and above described in connection with Figure 2 At diametrically opposed points and at the sides of the sleeve 209, as viewed in Figure 7, the sleeve 209 is provided with slots 2l6 and 2|] (see Figure 9), the slots extending through the bearing surface 209 above described. Extending into the slots 2l6-2l1 and slidably guided thereby are the bearing blocks 2 l 8 and 2 l 9, respectively, of trunnionsgenerally indicated at 2l8 and H9, the latter being provided with pivoting studs 2 l 8 and 2H", respectively. The trunnion members 2|8-2l9 are secured to the auxiliary or slidable sleeve H2 in any suitable manner, as by way of the screws 220 and 22l,'respectively (Figure 9).

The bearing blocks 2H! and 2l9 are somewhat shorter than the length in an axial direction of the slots 2l6 and 2H, and thus the trunnion members may be oscillated lengthwise of the supporting sleeve 209 and a similar oscillation or movement conveyed to the slidable sleeve 2 l 2 and hence to the movable lens 221; However, the trunnion blocks 2H3 and 219 are preferably snugly received between the side walls of the slots 2H5 and 2, respectively, and thus rotational movement of the inner sleeve 2|2 precluded. Due to the coaxial relations above described, movement of the sleeve 2l2 relative to the sleeve 209 achieves movement of the movable lens 221 along the optical axis of the lens system.

With the above described mounting (Figure 9) a nice compactness and ruggedness of construction are achieved while at the same time large and enduring bearing surfaces between the sleeves 209 and 2I2 are provided for maintaining the above described coaxial relation of the lenses throughout long continued use and throughout the repeated and rapid movements of the movable lens; it will be noted that, though the lenses (see Figure 9) are relatively close and compactly grouped, nevertheless, by reason of the telescopic character of the lens mounts 2 l4 and 2 IS with respect to the slidable sleeve 2l2 arid with respect to the main supporting sleeve 209, the annular chamber 222 is of large proportions to achieve the large bearing and supporting surfaces through which the movable sleeve 2l2 and the fixed sleeve 209 contact. This chamber 222, moreover, is virtually air-tight and thus access of foreign matter to the inside faces of lenses 226 and 229 and to the faces of lenses 221 and 228 is dependa-bly precluded. Inasmuch as the movable lens 221 with its supporting ring or annulus 2 l3 virtually sub-dvides this closed chamber 222, the supporting part-2l3 is apertured as at 223 to. permit displacement of air within the chamber 222 from one side of the lens 221 to the other as this lens is subjected to movement as hereinafter described and thus possible resistance to free and easy movement of the movable lens cut down.

' The movement of the lens 221, during exposure of the film, is eifected by means operating upon the studs 2l8 and 2l9 of the above described trunnions and illustratively and preferably this means includes a forked lever 230 (Figures 6 and '7) whose forked arms 230 and 230 (Figure 7) extend each to one side of the staionary supporting sleeve 209; the lever 230 is pivoted to swing about a horizontal axis preferably at an axis positioned intermediate the upper and lower ends of the lever 230 and illustra ively the pivotal mounting of the lever 230 may comprise two horizontally spaced posts 23i and 232 suitably secured to the flange 2l0 (Figures 6 and 7) of the supporting sleeve 209. These posts are horizontally spaced (Figure 7) and they extend at rightangles to the flange 2), receiving therebetween the spaced arms 230 and 230 of the lever 230 (Figure 7), these arms having studs 230 and 5 230 respectively, received in suitable hearings or apertures in the outer ends of the posts 23l232.

Each arm 230 and 230 of the lever 230 is itself bifurcated or forked, as is better shown in 10 Figure 6, where arm 230 appears in side elevation and from which the horizontally spaced but parallel portions 230 and 230 of the arm 230- are clearly shown. In a similar way arm 230 is bifurcated.

In between the parallel forked portions 230 and 230% (Figure 6) is received and thereby guided for vertical sliding movement a bearing block 233 suitably apertured to receive the pivot stud 2H! (Figures 6,7 and 9) of the trunnion'2l9. In a similar manner a bearing block 234 (Figure 7) is mounted for vertical sliding movement relative to the two forked portions of the arm 230 and is apertured to receive the pivot stud 2l8 of the trunnion 2l8.

- Thus, as the lever 230 is moved about the axis of the pivotal mounting provided by the spaced supports 23l-232, the upper forked or spaced arms 230*230 thereof are moved throughout a slight'arc in the general direction of the axis of the supporting sleeve 209 but due to the ivotal and slidable connection of the arms 230 -230 with the trunnions 2|9 and H8, respectively, the latter and hence the movable lens 221 partake of a straight-line movement in the direction of the axis of the sleeve 209.

Considering how the drive of the movable lens 221 from the main shaft 205 (Figure 6) of the camera mechanism, it is first to be noted that the inner face of the lower end of the lever 230 (Figure 6) is provided with a boss 230 whose face is concaved, thus to provide a seat for the head 234 (Figures 6 and 8) of a plunger 234 slidably mounted in the vertical right-hand end wall 235 of the upright frame portion 201 (Figures 6 and 8) of the camera l0.

In Figure 8 this plunger and certain related parts are better shown on a larger'scale. More specifically, it will be seenthat, in a suitable hole 236 in the wall 235 there extends a sleeve 23'! whose lower portion 238 is of lesser diameter and forms a sliding bearing for the plunger 234, both parts being of round cross-section. This portion 238 also is threaded to receive a nut 239 which, in coaction with a flange 240 at the innermost end of the larger-diametered part 231 serves to secure the sleeve 231238 in the hole 236 and hence to the wall 235.

In the space between the plunger 234 and the part 231 is accommodated a spring 2 whose upper end abuts against the head 234 of the plunger 234, thus tending to urge the plunger '234 inwardly through the wall 235.

Upon the interior and lower portions of the wall 235, however, I provide suitable spaced bearings 242243 (Figures 6, 7 and 8) and in these hearings is supported a shaft 244. At its righthand end, as viewed in Figures 7 and 8, shaft 244 has rigidly secured to it a lever or arm 245 whose upper end contacts with the inner end of the plunger 234, the spring 24| maintaining such contact throughout whatever oscillating or rotary movement, as hereinafter described, is given the shaft 244 and hence the arm 245. Thus a swinging of the shaft 244 about its axis effects,

As shown in Figure 6, a spring 225 acts upon the lens-moving lever 230 to make certain that that lever faithfully follows the movements of the plunger 234; spring 225 may conveniently be a tension spring and connected between lever 230 and the plate 201.

The shaft 244 is oscillated by mechanism driven from a shaft of the motion picture camera mechanism, illustratively the shaft 205 which, as above already noted, I have provided with a cam 206 (Figure 6) it is from cam 206 that the oscillatory motion of shaft 245 is derived. Illustratively and still referring to Figure 6, there is provided upon an interior wall of the camera casing !0 a bracket or stud 246 which provides'a pivot 29'! for a T-shaped lever 248 whose one end 2 18 bears against the peripheral face of the cam 206.

Any suitable coacting surfaces may be provided for these two contact parts to insure long life and resistance to wear and illustrativeiy fchese two parts may be made of hardened steel.

. The other end 248 of the lever 248 (see also Figure 8) bears against a spring-pressed plunger 249 that extends through the wall l0? (Figure 8) of the camera casing 0 and, is slidably guided thereby; the spring urges theplunger 249 inwardly of the casing l0 and illustratively the spring may take the form of a leaf spring 250 secured to the casing I0 and having its one end engaging against the under face of the head 249 of the plunger 249. The spring 250 insures that the plunger 249 is reciprocated faithfully in response to the oscillation of the lever 248 (Figure 8 and insures also that the latter lever 248 maintains contact with the'cam 206 and faithfully responds to the cam-shaped periphery of the cam 206.

The outer end of plunger 249 (Figures 8 and 6) hasa rounded head 249 which, in the position of the casing !0 relative to the supporting frame 200 -20l, as shown in Figure 8, engages an arm 25! on the shaft 244, arm 25i being in turn spring-pressed againstthe plunger 249 by. the action of spring 24! upon the plunger 234 (Figure 8). The operative connection between plunger 249 and lever 25! is, moreover, detachable or capable of disconnection, for purposes presently to be described.

, With the camera casing !0 moved along the ways 202-203 (Figure 6) into the position shown in Figure 8,,the film and shutter and relatedmechanism become displaced laterally of the optical axis of the lens system so that the operator may sight through the lens system, in the usual manner, to preview the scene or object which it is proposed to photograph. When the parts are in this relative position, the operative connection between plunger 249 (Figure 8) and the lever arm 25! on shaft 244 is established, where- 'upon operation of the crank !5 (Figure 6) while the operator is sighting through the lens system effects the above-described movement of the .movable lens 22'! (Figure 9) so that the operator can see with the naked eye what is later to be recorded upon the 111m itself.

When the operator is ready to photograph or.

, in'connection with Figures 6-9.

to expose the film, the camera casing I0 is moved along the ways 202'203 in adirection toward the right, as viewed in Figure 8, thus bringing the shutter and film gate and related parts into appropriate cooperative relation or alinement with 5 the optical axis of the lens system but in so doing the operative connection between plunger 249" and lever arm 25! on shaft 244 is disrupted but a new operative connection between plunger 249 and shaft 244 is established; this new operative connection is brought about by a second lever arm 252 (Figure 8) on shaft 244, lever arms 25! and 252 being of identical construction but spaced along the shaft 244 by the distance throughout which the camera casing I0 is displaceable relative to the supporting frame 200 to achieve the above-mentioned sighting position in the one case and the operative or photographing position in the other. Hence the oscillation of shaft 249 and likewise the movement of the movable lens 221 are achieved irrespective of the .relative positions of these parts, the 'yieldability imparted to arms 25! and 252 by reason of the spring 26! associated with the plunger 234' in coaction with the rounded or cam-like head 249 on the plunger 25 269 insuring ease and dependability of making or disrupting these operative connections. I Moreover, referring to Figures 6, '7 and 8, the operative connection between the lens-moving lever 230 and the plunger 234 is likewise detachable so that, in the case it is desired to make operative any other lens system (such as any one of the lens systems X, Y and Z of Figure 7) car- .ried by the rotatable plate 20'! (and which lens system may or may not embody the features of 35 lens action forming part of my invention), the operative connection between lever 230' and plunger 234 may be easily. disrupted or remade as the disk 201 is rotated out of the position shown in Figure 7', or is returned to that posi- 4 tion.

Reserving for later description certain details and action of the lens system of Figure 9 which, however, will already be clear in view of what has above been set forth in connection with Figures '45 1-5, I wish first to point out that I may, if desired, relate to the lens system and mechanism of Figures 6-9 inclusive a means for controlling the amount of light admitted-to the lens system synchronously with themovement of the mov- 5 able lens'and in so doing, and for purposes of illustration, I may and prefer to employ the four plates 16, 19, 96 and I08 and their operating mechanism for controlling the size of the rectangular opening 5 substantially exactly as 55 shown in Figures 1, 2 and 3, and in Figures 10 and 11 I have shown these parts and the related controlling mechanism, all, however, related to the plate 20'! and carried thereby, and related to the lens tube or mounting 209 above described 0 In view of the detailed description of the mounting of and control mechanism for these four plates with respect to Figures 1, 2 and 3, it will suflice, with respect to Figures 10 and 11, simply to notethat these 5 parts are all shown in the latter two figures and identified by the same reference characters employed in Figures 1, 2 and 3.

However, the lever 68 in Figures 10 and 11, instead of being actuated directly by a cam like 7 cam 66 of Figures 1 and 2, is actuated from the shaft 244 of Figure 8 through mechanism'Jwhich imparts to the lever 68, and hence to thefour plates that determine'the opening !!5 thronghv wh ch light is admitted to the lens systeni'and 7 hence to the film, the required synchronous motion; referring to Figures 10 and 11, I provide a link 253 pivoted as at 254, at its upper end, to the lever 68 and pivotally connected as at 255, at its lower end, to a'bell crank lever 256 which is pivoted as at 251 in a suitable bracket secured to or carried on the front face of the rotatable plate 201. The link 253 may be slightly curved as at 253 to by-pass the leaf spring 88 (see Figure 11).

'The vertical arm 256* of the bell crank lever 256 projects downwardly beyond the periphery of the plate 20'! (Figures 10 and 11) where it en identity to plunger 234 and the mounting of the latter is clearly apparent, being also springpressed inwardly. However, plunger 258 contacts with an arm 252 on shaft 244, like arm 252,

already above described, and due to the oscilla-' tion of shaft 244 in the manner already above describedand irrespective of whether the plunger 249 (Figure 8) contacts with arm 25| or 252, plunger 258 is caused to partake of a corresponding reciprocation and thus bell crank lever'256 (Figure 11) is correspondingly oscillated and the motion of oscillation transmitted to the lever 68 (Figures 10 and 11) with changes in the size of the light-emitting opening H that will be clear in view of what has already been set forth in connection with Figures 1, 2 and 3. As was the case with the mechanism of the latter figures, the changes in size of the light-emitting opening H5, in the apparatus of Figures and 11, take place in step with or in synchronism with the changes in position of the movable lens 221 (Figure 9) of the lens system.

Moreover, it will be seen that the operative connection between bell crank lever 256 (Figures 11 and 8) and the plunger 258 is detachable, just as is the connection between the lens-actuating lever 230 (Figure 6) with the plunger 234. Thus, ease-and speed of assembly or disassembly or replacement or change in position of the various parts may be readily achieved.

The specific form of lens system or rather of the individual lenses shown in Figure 9 has, as is now clear, the characteristics of action, correction and result above described in connection with the illustrative form of lens system or individual lenses of Figures 2 and 5, certain aspects of which are shown diagrammatically dealt with in Figure 12 and hence, as the crank l5 (Figure 6) is turned and the shaft 205 rotated, the lens 221 (Figure 9) is given an axial -movement in one direction and back again to its original position for each rotation of the shaft 205 and hence for each actuation 'of the shutter (not shown) and hence also for each exposure of the successive frames on the motion picture film. The film, where it is a motion picture film, remains stationary during the interval of time that the shutter is effective to expose the frame on the film and the shutter closes off the light from access to the film, thus to shield the film, while the film is being moved by the shuttle mechanism to bring the next frame thereof to position to be affected by the images formed by the lens system. 4

Preferably the relation between the cam surfaces of cam 206 (Figure 6) to the shutter drive is such that the lens 221 is given its full range of movement in one direction while the film is exposed and is returned in the opposite direction while the shutter is closed. Thus, each frame of the film has impressed upon it, due to the action of the lens system and due to the coaction of the various characteristics of the fixed 5 lenses with the characteristics of the movable lens as the latter is moved during exposure, a multitude, infinite in number, of registering images of the scene or object, each image corresponding to a different focus of the lens system 10 and hence corresponding to a different plane of sharpness. .As already above noted, the in-focus and out-of-focus images are all of the same size and register on the film or film plane, and thus clarity, sharpness, and absence of blurring, are 15 dependably achieved regardless of the depth of the scene or regardless of the varying distances from the camera of different portions of or objects in the scene.

Actuated synchronously with the above described movement of the movable lens 221 is, as will now be clear, the lever 68 (Figures 10 and 11) whereby the size of the light-emitting opening I I 5 formed by the plates l6, 19, 9G and I08 is varied, and the mechanism is preferably so related, as already above described in connection with Figures 6--11 inclusive, that, as the lens 22'! moves to bring into efiect planes of sharpness more remote from the camera, these plate members are moved apart from each other so as to increase the size of the opening I I5, and vice versa. Thus, as objects in or portions of the scene at varying distances from the camera are brought into sharpness in the image affecting the film, the amount of light admitted to the film through the lens system is changed, the amount of light being increased for objects in or portions of the scene relatively far away from the camera and being decreased for portions of or objects in the scene relatively near the camera. Though I achieve highly efiicient and excellent results without the use of this coacting light-varying mechanism and hence may carry on photography 1 without that mechanism, I find it, under certain circumstances of use, of important advantage and coaction.

Considering now more in detail certain structural details of the preferred and specific form of lenses making up the system of Figure 9, it is first to be understood that the various optical characteristics and coactions and corrections above described in considerable detail in connection with the lenses 26, 27, 28 and 29 with particular reference to the optical diagrams of Figures 5 and 12, apply to or are embodied in the specific lens system of Figure 9, and those numerous and detailedconsiderations need not therefore be at this point repeated, it being understood that, depending upon such factors as the character of the glasses employed and their in- 0 dices of refraction, the physical structure or appearance of the individual lenses may vary though still embodying the principles and optical characteristics and corrections of my invention as above already set forth in detail. 5

of the optical principles and optical prescriptions and corrections aboveset forth in detail:-

Lens 226 (Figure 9).This lens is the postive front'lens; it is made of a glass having an index dispersion of 41.0. The radius of curvature offace c is 23.0 mm. and the radius of curvature of face d is 16.0 mm. It has a thickness at the optical axis of 0.66 mm. and it has a diameter of 17.0

Lens 228.-This lens is a concavo-convex lens, beingmade of a glass havingan index of refractionfor the d line of 1.5798 and a dispersion of 41.0. The radius of curvature of face 6. is 11.5-

mm. and the radius of curvature of face I is 13.0 mm. It has a' thickness of 1.0 mm. at the optical axis and it has a diameter of 14.5 mm.

Lens 229.This lens is a concave-convex lens, being made of aglass having an index of refraction for the d line or 1.6100 and a dispersion of 55.8. The radius of curvature of face g is 64.0 mm. and the radius of curvature of face it is 17.5

mm. It has a thickness at the optical axis of 2.1

mm. and its diameter is 14.5 mm.

The spacing between lenses 229 and 228, that is the distance along the optical axis from face 9 to face f is 0.03 mm. The spacing between lens 228 and lens 226, that is the distancealong the optical axis from face e to face b is 5.26 mm.

The range of movement of lens 221 sufficient to move the focus or plane of sharpness from a point about 3 feet from the lens to a point infinitely remote is 0.30 mm. ,That is if the next plane of sharpness to be brought into effect is desired to be approximately 3 feet to the right of the lens system as-viewed in Figures 6-9, the lens 221 assumes a position such that the spacing between the faces and b is 1.25 mm. while, to cause the plane of sharpness or focus to sweep through the entire-depth of the scene during exposure, the lens 221 is moved to a point such that this spacing between faces 0 and b is 0.95 mm., the focusor depth of sharpness at that spacing being substan tially at infinity. During exposure, therefore, and whereit is desired to change the focus-or plane of sharpness from one of the above-mentioned limits progresslvelyto the other of these limits, the lens 221 is given a movement of about 0.3 mm. to change the spacing between the faces 0 and b from 0.95'mm. progressively to 1.25 mm.

' The spacing from face h (Figure 9) of the in-' nermost lens 229 to the film plane or film is the 1 back focus and is substantially 47.3 mm. andthe focusv or distance of the optical lens system to the light sensitive surface or film plate .orfilm is substantially 50 mm.

The mechanical or physicaldata immediately Y during each exposure, the movement being synchronized with the opening action of the shutter and, where the camera is a motion picture camera, taking place during a halting in the movement of the film where the motion picture cam- .of the scene are of the same size and register on system all of these in-focus and out-of-focus im ages of the same object or of the same portion the film. Thus, there is rio blurring and a nice evenness of result appears on the film and on any positive, print, or projection, that results from the initial negative.- Other aspects of the unique results achieved have been dealt with hereinabove' and will now be entirely clear. i

It will thus be seen that there has been provided in this invention an apparatus in which the various objects hereinbefore set forth, together with many thoroughly practical advantages are sue-'25 cessfully achieved.

As many possible embodiments may be made of the above invention, and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth. or shown in the accompanying drawings, is to beinterpreted as illustrative and not in a limiting sense.

I claim:

1. In photographic apparatus, in'combination. a lens system adapted to form images of objects in a scene, means adapted to move a strip of film through a position to be affected by said images,- means adapted to control the passage of light rays through said lens system and to said film 40 to expose successive portions of said strip to said images each for an interval of .time, means adapted during each-of said intervals of time to change the relation between said lens system and the portion of said strip being exposed to bring different planes of the scene into sharpness in the image affecting said film, and means adapted durmg each of said intervals to change, the amount of light admitted to the strip through said lens system as said different planes are brought into sharpness.

2. In photographic apparatus, in combination,

' a lens 'system adapted to form images of objects in a scene, means adapted to move a strip of film through a position to be affected by said images, means adapted to control the passage of light rays through said lens system and to said filmto expose successive portions of said strip to said images each for an interval of time, a rotating shaft for driving said last means, a mechanism 00 adapted when actuated to change the relation between said lens system and the portion of said strip being exposed to bring different planes in the scene into sharpness in the image affecting said film, andmeans driven from said rotating o5 shaft for actuating said mechanism during an exposure of aportion of said film. Y

3. In photographic apparatus, in combination, a lens system adapted to form images of objects in a scene, means adapted to move a strip of film through a position to be affected by said images,

' means adapted to control the passage of light rays through said lens system and to said film to expose successive portions of said strip to said images each for an interval of time, a rotating :5

shaft for driving said last means, a mechanism adapted when actuated to change the relation between said lens system and the portion of said strip being exposed to bring different planes in the scene into sharpness in the image aifeeting said film, means driven from said rotating shaft for actuating said mechanism, a second mechanism adapted when actuated to change the amount of light admitted to said film through said lens system, and means driven from said rotating shaft for actuating said second mecha- 4. In photographic apparatus, in combination, a lens system adapted to form images of objects in a scene, means adapted intermittently to move a strip of film through a position to be aifected by said images, said lens system including a positive front lens, a negative lens, and corrective lens means, the positive lens being double convex and having faces whose radii of curvature are respectively on the order of 16 and 41 millimeters, said negative lens being double concave and having faces whose radii of curvature are respectively on the order of 23 and 13 millimeters, said corrective lens means comprising two concavo-convex lenses, the first of which has faces whose radii of curvature are respectively on the order of 12 and 13 millimeters and the second of which has faces of radii of curvature on the order of 64 and 18 millimeters, said lenses being made of glass having an index of refraction on the order of 1.6, whereby upon movement of said negative lens relative to the remaining lenses, said lens system changes the focus from a plane adjacent the lens system relatively remote therefrom and main-- .tains the same size of image on the exposed portion of said film for all in-focus and out-of-fo'cus images throughout the range of change of focus, a shutter for controlling the passage of light rays to said film, means adapted to open said shutter for an interval of time at each stoppage of said film, means adaptedduring each of said intervals of time to move said movable lens so as to move the focus of the lens system in one direction between a plane relatively near thereto and a plane at a substantial distance away therefrom, and adapted between said intervals of time to move said lens in the opposite direction, adjustable means adapted to control the amount of light admitted to said film through said lens system, and means adapted to affect said last means to progressively vary the amount of light admitted to said film, during each of said intervals of time, as the foeus'of the lens system is changed.

5. A camera for recording pictures that exhibit the illusionof relief or depth of the scene or object itself, comprising, in combination, means for supporting a strip of sensitized photographic film, a lens system through which a portion of said film is exposed to the scene or object, said lens system comprising a positive front lens, a positive rear corrective lens, and a spaced intermediate negative lens, said system having fixed principal planes'jmeans mounting said negative lens for axial movement, mechanism for elfecting movement of said strip of film relative to said lens system and for exposing successive portions thereof to light rays passing through said lens system, and mechanism operating synchronously with said first-mentioned mechanism for moving the movable lens within its range of movement during each exposure of the successive portions of said 6. A photographic camera for impressing upon a sensitized photographic element a plurality of images of an object or scene, each image corresponding to a different plane of sharpness and each image being of the same size, comprising in combination, means for holding a sensitized camera element, a lens system through which said sensitized element is exposed to a scene or object, said lens system comprising a plurality of lens means, coaxially arranged, at least one of said lens means being movable axially throughout a certain range to change the focal length of the lens system, said lens system having fixed principal planes throughout the range of movement of said movable lens means, whereby said images of said object or scene are in substantial registry,. a shutter for exposing said sensitized element through said lens system to said scene or object, means-for moving said movable lens means within said range of movement, a variable diaphragm comprising a plurality of relatively movable members for controlling the amount of light transmitted from the scene or object through the lens system onto said sensitized camera element, means adapted upon actuation to relatively shift movable members of said diaphragm thereby to vary the aperture provided by said dia- 5 phragm, and means operating during the interval of time that said sensitized element is exposed by said shutterfor operating said lens-moving means and said diaphragm-actuating means.

7. A photographic camera for impressing upon a sensitized photographic element a plurality of images of an object or scene, each image corresponding to a different plane of sharpness and each image being of the same size, comprising, in combination, means for holding a sensitized camera element, a lens system through which said sensitized element is exposed to a scene or object, said lens system comprising a plurality of axially arranged lenses, an intermediate lens of which is a negative lens and is movable axially 40 within a certain range relative to the remaining lenses, said lens system having, throughout said certain range of movement of said negative lens, fixed principal planes, whereby said images are in substantial registry on the sensitized element for all posit-ions of said movable lens, a shutter, a rotatable member for moving said'shutter to expose said sensitized element for a certain time interval, means mounting said movable lens for movement axially and within said certain range, and cam means driven from said rotatable member for actuating said lens-mounting means during the interval of exposure of said sensitized element.

8. A photographic camera for impressing upon a sensitized photographic element a plurality of images of an object or scene, each image corresponding to a difierent plane of sharpness and each image being of the same size, comprising, in combination, means for holding a sensitized camera element, a lens system through which.

. said sensitized element is exposed to a scene or 'said movable lens within said range of movement, 7

and. actuating mechanism operatively interrelating said shutter and said lens-moving means for operating said lens-moving means during the period of time when said shutter exposes said ject or scene having a radius of curvature on the order of 16 mm., said negative lens being double concave and having faces whose radii of curvature are respectively on the order of 23 mm. and 13 mm., said corrective lens means comprising two lenses at least one of which has a concave face, and means for moving'said negative lens along the optical axis throughout a relatively small distance, said positive front lens and said negative lens being image forming and being corrected to giveconcentricity of circles of confusion produced by changes of focus with respect to the in-focus images of any point objects, when said movable lens is moved to change the focus.

10. In photographic apparatus, in combination, a lens system for forming images of an object or a scene with a change in focus and for causing infocus and out-of-focus images to register, said lens system including two groups of lenses, a front group and a rear group, said front group comprising at least two lenses and being the image-forming lenses and the rear group being correctivelenses and including two lenses, said front group comprising a positive front lens and a negative'lens, means mounting said negative lens for movement along the optical axis within a certain range, and means for moving said negative lens along the optical axis, said lenses having-corrections so that change of focus takes place during movement of said negative lens within said range without shifting the positions of the principal planes.

11. A lens system comprising a plurality of lenses, one of which is movable, said lens system comprising, in order, a front lens (L226), a movable lens (L221), a third lens '(Lm) and a fourth lens (L229), the lenses being made and spaced from each other substantially in conformity with the followingconstructional data:

Ims rs= 16.0 mm. 7 Tas=3.5 mm. v

n=41.0 mm. 'Lm r=23.0 mm. Tcd=0.66 mm. Tip- 16.0 mm. Sue=5.25 mm. L228 1"e=1l.5 mm. Tef=1.0 mm.

r1=13.0 mm. L229 7 :64.0 mm. Tr-11:2,]. mm.

Th=17.5 mm. Sz- =0.03 mm.

' in which r' are radii of curvature, T are lens 12. In'apparatus of the character described, in

combination, a motion picture camera having a connection means actuated when said plate is moved;

13. In apparatus of the character described, in combination, a motion picture camera having a' driving element for driving the film, said camera including a lens-carrying plate, means movably mounting said plate relative to said camera, a plurality of lens systems carried by said plate including a lens system one of whose lenses is movable, and means including a driving train extending from said driving element to said movable lens, mechanism including an arm carried by said plate and adapted upon oscillation to move said movable lens, said arm being movable with said plate, and means operable from said l5 driving element for engaging said arm when said plate is moved to bring said last-mentioned lens system into operative position, for oscillating said arm.

in combination, a camera having means for holding a sensitized photographic element and a shutter, means for operating said shutter to expose said sensitized photographic element, aJens-carrying plate, means movably mounting said plate relative to said camera. a plurality of lens systems carried by said plate including a lens system one of whose lenses is movable, and means including a driving train extending from said shutter-operating means to said movable lens, said driving train including disruptable connection means actuated when said plate is moved.

15. In apparatus of the character described, in combinati0n,'a camera having means for holding a sensitized photographic element, lens means through which said sensitized element may be exposed,-a plate-like member, means movably mounting said plate-like member for movement relative to said camera, a variable diaphragm carried by said plate-like member, and means for varying said diaphragm during exposure of said sensitized element and including a driving train, a part of which is carried by said camera and another part is carried by said plate-like member and is operatively connected to said variable diaphragm, said driving train including disruptable connection means actuated when said plate-iii: member is moved.

16. In photographic apparatus, in combination,

a lens system adapted to form images of objects 3 in a scene, means for holding a sensitized photographic element in a position to be aifected by said images, said lens system including a positive 14. In apparatus of the character 'described, 20

front lens, a negative lens, and corrective lens ly on the order of 23 and 18 millimeters, said corfdrivlng element for driving the film, said camera including a lens-carryingplate, means movably mounting said plate relative to said camera, a

plurality of lens systems carried by said plate able lens, said driving train including disruptable rective lens means comprising two concave-convex lenses, thefirst of which has faces whose radii of curvature are respectively on the order of 12 and 13 millimeters and the second of which has and 18 millimeters, said lenses-being made of glass having an index of'refraction ,on the order of 1.6, whereby upon movement of said negative lens relative to the remaining lenses, said lens faces of radii of curvature on the order of 64 05 system changes the focus from a plane adjacent 7 the lens system relatively remote therefrom and maintains substantially the same size of image 'ontheex'posed portion of said film for all infocus and out-of-focus images throughout the 

